Preform gram weight is the single biggest driver of both bottle performance and resin cost. Pick it well and you balance top-load, burst resistance and material spend; pick it badly and you over-stretch the wall or waste PET on every shot.
Weight follows volume — and application
As bottle volume grows, the preform must carry more material to keep an even, blow-able wall. Delta El Nile for Industry’s public range runs from a 9 g 330 ml water preform to a 668.5 g 19 L returnable Co-PET preform. Carbonated drinks (CSD) sit heavier than still water at the same volume because the wall must hold CO₂ pressure.
Weight range by application
Delta El Nile for Industry’s public catalogue maps each application to a weight band, neck finish and resin grade:
| Application | Bottle volume | Weight range | Neck finish | Resin IV / AA |
|---|---|---|---|---|
| Water | 330 ml – 19 L | 9 – 668.5 g | 29/25 · 48 mm · 55 mm | 0.76–0.80 dl/g · AA <6 ppm |
| Carbonated (CSD) | 250 ml – 2.5 L | 13 – 53.6 g | PCO 1881 · PCO 1810 | 0.84 dl/g · AA <10 ppm |
| Edible oil | 750 ml – 5 L | 17.6 – 84 g | 29/21 · 42/36 | 0.84 dl/g · AA <10 ppm |
| Juice & milk | 250 ml – 1.25 L | 11 – 32 g | 32/15 · 38 mm | 0.76–0.80 dl/g · AA <6 ppm |
5-gallon / 19 L returnables run a higher IV band (0.84–0.87 dl/g). Browse every weight in the Product Catalog, or filter by application, neck and volume in the Product Finder.
The lightweighting trade-off
Lightweighting lowers cost and carbon, but every gram removed raises the stretch ratio. Past a point you lose top-load and risk stress-whitening. Validate any aggressive weight against the bottle geometry before committing.
- Use the Product Finder to see every weight available for your application, neck and volume.
- Check stretch ratios and wall behaviour in the Preform → Bottle Advisor.
- Compare candidates on the Compare tool (net/gross weight + packaging overhead).
Worked example
For a 600 ml still-water bottle on a 29/25 neck, the catalogue weight is DEN-WATER-12-29-25 (12 g). Stepping down to 10.5 g is possible on a shorter bottle but raises the stretch ratio — confirm before quoting.